The choroid plexus in health and in disease: Dialogues into and out of the brain (original) (raw)

The choroid plexus-cerebrospinal fluid system: from development to aging

Current topics in developmental biology, 2005

The function of the cerebrospinal fluid (CSF) and the tissue that secretes it, the choroid plexus (CP), has traditionally been thought of as both providing physical protection to the brain through buoyancy and facilitating the removal of brain metabolites through the bulk drainage of CSF. More recent studies suggest, however, that the CP-CSF system plays a much more active role in the development, homeostasis, and repair of the central nervous system (CNS). The highly specialized choroidal tissue synthesizes trophic and angiogenic factors, chemorepellents, and carrier proteins, and is strategically positioned within the ventricular cavities to supply the CNS with these biologically active substances. Through polarized transport systems and receptor-mediated transcytosis across the choroidal epithelium, the CP, a part of the blood-CSF barrier (BCSFB), controls the entry of nutrients, such as amino acids and nucleosides, and peptide hormones, such as leptin and prolactin, from the per...

A balanced view of choroid plexus structure and function: Focus on adult humans

Experimental neurology, 2015

Recently tremendous progress has been made in studying choroid plexus (CP) physiology and pathophysiology; and correcting several misconceptions about the CP. Specifically, the details of how CP, a locus of the blood-CSF barrier (BCSFB), secretes and purifies CSF, generates intracranial pressure (ICP), maintains CSF ion homeostasis, and provides micronutrients, proteins and hormones for neuronal and glial development, maintenance and function, are being understood on a molecular level. Unequivocal evidence that the CP secretory epithelium is the predominant supplier of CSF for the ventricles comes from multiple lines: uptake kinetics of tracer (22)Na and (36)Cl penetration from blood to CSF, autoradiographic mapping of rapid (22)Na and (36)Cl permeation (high permeability coefficients) into the cerebroventricles, CSF sampling from several different in vivo and in vitro CP preparations, CP hyperplasia that increases CSF formation and ICP; and in vitro analysis of CP ability to transp...

Choroid plexus and the blood–cerebrospinal fluid barrier in disease

Fluids and Barriers of the CNS, 2020

The choroid plexus (CP) forming the blood–cerebrospinal fluid (B-CSF) barrier is among the least studied structures of the central nervous system (CNS) despite its clinical importance. The CP is an epithelio-endothelial convolute comprising a highly vascularized stroma with fenestrated capillaries and a continuous lining of epithelial cells joined by apical tight junctions (TJs) that are crucial in forming the B-CSF barrier. Integrity of the CP is critical for maintaining brain homeostasis and B-CSF barrier permeability. Recent experimental and clinical research has uncovered the significance of the CP in the pathophysiology of various diseases affecting the CNS. The CP is involved in penetration of various pathogens into the CNS, as well as the development of neurodegenerative (e.g., Alzheimer´s disease) and autoimmune diseases (e.g., multiple sclerosis). Moreover, the CP was shown to be important for restoring brain homeostasis following stroke and trauma. In addition, new diagnos...

Cerebrospinal Fluid Secretion by the Choroid Plexus

Physiological Reviews, 2013

The choroid plexus epithelium is a cuboidal cell monolayer, which produces the majority of the cerebrospinal fluid. The concerted action of a variety of integral membrane proteins mediates the transepithelial movement of solutes and water across the epithelium. Secretion by the choroid plexus is characterized by an extremely high rate and by the unusual cellular polarization of well-known epithelial transport proteins. This review focuses on the specific ion and water transport by the choroid plexus cells, and then attempts to integrate the action of specific transport proteins to formulate a model of cerebrospinal fluid secretion. Significant emphasis is placed on the concept of isotonic fluid transport across epithelia, as there is still surprisingly little consensus on the basic biophysics of this phenomenon. The role of the choroid plexus in the regulation of fluid and electrolyte balance in the central nervous system is discussed, and choroid plexus dysfunctions are described i...

Molecular anatomy and functions of the choroidal blood-cerebrospinal fluid barrier in health and disease

Acta Neuropathologica, 2018

The barrier between the blood and the ventricular cerebrospinal fluid (CSF) is located at the choroid plexuses. At the interface between two circulating fluids, these richly vascularized veil-like structures display a peculiar morphology explained by their developmental origin, and fulfill several functions essential for CNS homeostasis. They form a neuroprotective barrier preventing the accumulation of noxious compounds into the CSF and brain, and secrete CSF, which participates in the maintenance of a stable CNS internal environment. The CSF circulation plays an important role in volume transmission within the developing and adult brain, and CSF compartments are key to the immune surveillance of the CNS. In these contexts, the choroid plexuses are an important source of biologically active molecules involved in brain development, stem cell proliferation and differentiation, and brain repair. By sensing both physiological changes in brain homeostasis and peripheral or central insults such as inflammation, they also act as sentinels for the CNS. Finally, their role in the control of immune cell traffic between the blood and the CSF confers on the choroid plexuses a function in neuroimmune regulation and implicates them in neuroinflammation. The choroid plexuses, therefore, deserve more attention while investigating the pathophysiology of CNS diseases and related comorbidities.

The choroid plexus--cerebrospinal fluid system: undervaluated pathway of neuroendocrine signaling into the brain

Acta neurobiologiae experimentalis, 2008

The cerebrospinal fluid (CSF) is a major part of the extracellular fluid of the central nervous system. The function of the CSF and the tissue that secretes it, the choroid plexus (CP) has traditionally been thought as providing the brain with essential nutrients, removing products of neuronal activity of the central nervous system, and providing mechanical support for the brain's fragile cellular network. More recent studies suggest, however, that the CP and CSF system play a much more active role in the function of the central nervous system being a target, source and pathway for neuroendocrine signaling within the brain.

TRANSPORT FUNCTION: WHICH CHOROID PLEXUS IS MORE ACTIVE?

The choroid plexus (CP) is present in brain ventricles. It is responsible for cerebrospinal fluid (CSF) secretion and various vital functions. Special proteins present in choroidal epithelium play important roles in CSF production and energy metabolism.This study aims to compare between the lateral and fourth ventricles CPs using monocarboxylate transporter 1 (MCT1), transport marker, to evaluate the functional activity of this tissue in the two regions.Ten adult male albino rats were used to study the histological features of the CPs and to study the functional activity by quantitative immunohistochemical labeling with MCT1.Reactions intensities for MCT1 marker in the fourth ventricle CP was significantly higher with a wider spectrum of transport activity than those in the lateral ventricle. Both CPs displayed ?non-reactive? cells to this marker.The CP of the fourth ventricle had more functional activity than the CP of the lateral ventricle. Immunohistochemical detection of transport marker went along with findings of other histological and biochemical studies to define the CP as a highly dynamic structure with regional variations forming a continuum of one entity tissue capable of functional adaptation according to body needs.