Physiological Stimulation of the Choroid Plexus and Experimental Poliomyelitis

1919 ◽  
Vol 49 (1) ◽  
pp. 73
Author(s):  
S Flexner ◽  
H L Amoss ◽  
F Eberson
1991 ◽  
Vol 260 (3) ◽  
pp. H902-H908 ◽  
Author(s):  
J. L. Williams ◽  
M. M. Thebert ◽  
K. A. Schalk ◽  
D. D. Heistad

The goal of this study was to examine effects of stimulation of the area postrema on blood flow to choroid plexus and brain. In chloralose-anesthetized dogs, the area postrema was stimulated electrically, and arterial pressure and blood gases were maintained at control levels. We measured blood flow to brain and choroid plexus of the fourth and lateral ventricles with microspheres. Stimulation of the area postrema at 10 +/- 2 microA (means +/- SE), which was the threshold for changes in arterial pressure and heart rate, decreased blood flow to choroid plexus of the fourth and lateral ventricles by 41 +/- 11 and 51 +/- 6%, respectively (from 349 +/- 38 and 503 +/- 46 ml.min-1.100 g-1, respectively). Stimulation at high amplitudes (67 +/- 5 microA) produced only slightly greater decreases in blood flow to choroid plexus. In contrast, cerebral blood flow did not change during stimulation of the area postrema. After blockade of autonomic ganglia with intravenous chlorisondamine, stimulation of the area postrema had minimal effects on blood flow to choroid plexus. The results indicate that stimulation of the area postrema decreases blood flow to choroid plexus, probably by an autonomic mechanism. We speculate that the area postrema may play a role in regulation of volume in the central nervous system by modulating production of cerebrospinal fluid.


Author(s):  
Daniel Hoyer ◽  
Christian Waeber ◽  
Philippe Schoeffter ◽  
JoseMaria Palacios ◽  
Anant Dravid

1918 ◽  
Vol 27 (6) ◽  
pp. 679-687 ◽  
Author(s):  
Simon Flexner ◽  
Harold L. Amoss ◽  
Frederick Eberson

The experiments recorded in this paper serve, in the first place, to confirm the experiments of Dixon and Halliburton on the stimulating effect of intravenous injections of extracts of choroid plexus in the secretion of the cerebrospinal fluid, and extend their observations to monkeys. They bring out also the variable effects of the virus of poliomyelitis, variations affected by the quality of the virus and also by the individual powers of resistance to infection possessed by individual monkeys. These factors of variation must be taken into account in performing and interpreting experiments on infection and particularly those on immunity and specific therapy in relation to poliomyelitis. In general it may be said that experimental infection by way of the blood is not easy to produce in monkeys unless some contributing factor, such as the existence of a coincident aseptic meningitis, operates at the same time. And yet Experiments 1 and 2 show that when the strength of the virus is great the injection of relatively considerable quantities suffices to induce infection and paralysis, but not in all instances. The chief outcome of the experiments has been to determine the fact that when the intravenous inoculation of the virus does not in itself suffice to induce infection and paralysis, the intravenous injection of extracts of the choroid plexus, which in themselves excite the secretory functions which preside over the formation of the cerebrospinal fluid, is powerless to modify this result. This fact would seem to be of interest and importance, since it has already been shown that very slight structural changes in the meningeal-choroidal complex suffice to make possible or certain infection under these circumstances. Apparently mere augmentation, from time to time, of the secretory functions of the choroid plexus, through intravenous injection of an extract of the choroid plexus and while the virus is still circulating, is insufficient to insure passage of the virus from the blood into the nervous tissues, upon which infection depends. Neither does the augmentation exercise a restraining influence on the development of infection otherwise capable of taking place.


2021 ◽  
Vol 22 (16) ◽  
pp. 8857
Author(s):  
Samantha D. Francis Stuart ◽  
Alice R. Villalobos

Choroid plexus (CP) sequesters cadmium and other metals, protecting the brain from these neurotoxins. These metals can induce cellular stress and modulate homeostatic functions of CP, such as solute transport. We previously showed in primary cultured neonatal rat CP epithelial cells (CPECs) that cadmium induced cellular stress and stimulated choline uptake at the apical membrane, which interfaces with cerebrospinal fluid in situ. Here, in CPECs, we characterized the roles of glutathione (GSH) and Zinx supplementation in the adaptive stress response to cadmium. Cadmium increased GSH and decreased the reduced GSH-to-oxidized GSH (GSSG) ratio. Heat shock protein-70 (Hsp70), heme oxygenase (HO-1), and metallothionein (Mt-1) were induced along with the catalytic and modifier subunits of glutamate cysteine ligase (GCL), the rate-limiting enzyme in GSH synthesis. Inhibition of GCL by l-buthionine sulfoximine (BSO) enhanced stress protein induction and stimulation of choline uptake by cadmium. Zinx alone did not induce Hsp70, HO-1, or GCL subunits, or modulate choline uptake. Zinx supplementation during cadmium exposure attenuated stress protein induction and stimulation of choline uptake; this effect persisted despite inhibition of GSH synthesis. These data indicated up-regulation of GSH synthesis promotes adaptation to cadmium-induced cellular stress in CP, but Zinx may confer cytoprotection independent of GSH.


2014 ◽  
Vol 306 (5) ◽  
pp. R291-R303 ◽  
Author(s):  
Robin K. Young ◽  
Alice R. A. Villalobos

The choroid plexus epithelium forms the blood-cerebrospinal fluid barrier and accumulates essential minerals and heavy metals. Choroid plexus is cited as being a “sink” for heavy metals and excess minerals, serving to minimize accumulation of these potentially toxic agents in the brain. An understanding of how low doses of contaminant metals might alter transport of other solutes in the choroid plexus is limited. Using primary cultures of epithelial cells isolated from neonatal rat choroid plexus, our objective was to characterize modulation of apical uptake of the model organic cation choline elicited by low concentrations of the contaminant metal cadmium (CdCl2). At 50–1,000 nM, cadmium did not directly decrease or increase 30-min apical uptake of 10 μM [3H]choline. However, extended exposure to 250–500 nM cadmium increased [3H]choline uptake by as much as 75% without marked cytotoxicity. In addition, cadmium induced heat shock protein 70 and heme oxygenase-1 protein expression and markedly induced metallothionein gene expression. The antioxidant N-acetylcysteine attenuated stimulation of choline uptake and induction of stress proteins. Conversely, an inhibitor of glutathione synthesis l-buthionine-sulfoximine (BSO) enhanced stimulation of choline uptake and induction of stress proteins. Cadmium also activated ERK1/2 MAP kinase. The MEK1 inhibitor PD98059 diminished ERK1/2 activation and attenuated stimulation of choline uptake. Furthermore, inhibition of ERK1/2 activation abated stimulation of choline uptake in cells exposed to cadmium with BSO. These data indicate that in the choroid plexus, exposure to low concentrations of cadmium may induce oxidative stress and consequently stimulate apical choline transport through activation of ERK1/2 MAP kinase.


1974 ◽  
Vol 23 (3) ◽  
pp. 754-758 ◽  
Author(s):  
Jenny T. Johnson ◽  
L. hannon^Holloway ◽  
S. Richard Heisey ◽  
Jerry B. Hook

1981 ◽  
Vol 1 (3) ◽  
pp. 245-266 ◽  
Author(s):  
Maria Lindvall ◽  
Christer Owman

The choroid plexuses of all ventricles receive a well-developed adrenergic and cholinergic innervation reaching both the secretory epithelium and the vascular smooth muscle cells. Also peptidergic nerves, containing vasoactive intestinal polypeptide, are present but primarily associated only with the vascular bed. A sympathetic inhibitory effect on the plexus epithelium has been indicated in determinations of carbonic anhydrase activity and by studies of various aspects of active transport in isolated plexus tissue. Pharmacological analysis in vitro has shown the choroidal arteries to possess both vasoconstrictory α-adrenergic and vasodilatory β-adrenergic receptors. Electrical stimulation of the sympathetic nerves, which originate in the superior cervical ganglia, induces as much as 30% reduction in the net rate of cerebrospinal fluid (CSF) production, while sympathectomy results in a pronounced increase, about 30% above control, in the CSF formation. There is strong reason to believe that the choroid plexus is under the influence of a considerable sympathetic inhibitory tone under steady-state conditions. From pharmacological and biochemical experiments it is suggested that the sympathomimetic reduction in the rate of CSF formation is the result of a combined β-receptormediated inhibition of the secretion from the plexus epithelium and a reduced blood flow in the choroid plexus tissue resulting from stimulation of the vascular α-receptors. The choroid plexus probably also represents an important inactivation site and gate mechanism for sympathomimetic amines, as evidenced by considerable local activity of catechol- O-methyl transferase and monoamine oxidase, primarily type B. The CSF production rate is also reduced by cholinomimetic agents, suggesting the presence of muscarinic-type cholinergic receptors in the choroid plexus.


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