Cerebrospinal Fluid, Brain Electrolytes Balance, and the Unsuspected Intrinsic Property of Melanin to Dissociate the Water Molecule.

BACKGROUND & OBJECTIVE: Regulation of composition, volume and turnover of fluids surrounding the brain and damp cells is vital. These fluids transport all substances required for cells and remove the unwanted materials. This regulation tends to act as barrier to prevent free exchange of materials between the brain and blood. There are specific mechanisms concerned with fluid secretion of the controlled composition of the brain, and others responsible for reabsorption eventually to blood and the extracellular fluid whatever their composition is. The current view assumes that choroidal plexuses secrete the major part of Cerebrospinal Fluid (CSF), while the Blood-Brain Barrier (BBB) has a much less contribution to fluid production, generating Interstitial Fluid (ISF) that drains to CSF. The skull is a rigid box; thereby the sum of volumes occupied by the parenchyma with its ISF, related connective tissue, the vasculature, the meninges and the CSF must be relatively constant according to the Monroe-Kellie dogma. This constitutes a formidable challenge that normal organisms surpass daily. The ISF and CSF provide water and solutes influx and efflux from cells to these targeted fluids in a quite precise way. Microvessels within the parenchyma are sufficiently close to every cell where diffusion areas for solutes are tiny. Despite this, CSF and ISF exhibit very similar compositions, but differ significantly from blood plasma. Many hydrophilic substances are effectively prevented from the entry into the brain via blood, while others like neurotransmitters are extremely hindered from getting out of the brain. Anatomical principle of the barrier and routes of fluid transfer cannot explain the extraordinary accuracy of fluids and substances needed to enter or leave the brain firmly. There is one aspect that has not been deeply analyzed, despite being prevalent in all the above processes, it is considered a part of the CSF and ISF dynamics. This aspect is the energy necessary to propel them properly in time, form, space, quantity and temporality. CONCLUSION: The recent hypothesis based on glucose and ATP as sources of energy presents numerous contradictions and controversies. The discovery of the unsuspected intrinsic ability of melanin to dissociate and reform water molecules, similar to the role of chlorophyll in plants, was confirmed in the study of ISF and CSF biology.

Ultrastructural study of the lateral ventricle choroid plexus in experimental hydrocephalus in Wistar rats.

Hydrocephalus is one of the most frequent and complex neurological diseases characterized by the abnormal buildup of cerebrospinal fluid (CSF) in the ventricles of the brain, due to an altered CSF dynamics. To detect possible ultrastructural alterations of the lateral ventricles choroid plexus (responsible for the CSF production), rats seven days after birth were submitted to an intracisternal injection of 20% kaolim (hydrated aluminum silicate) for the hydrocephalus induction. Twenty-eight or 35 days after injection, injected animals and respective controls were processed for observation under a transmission electron microscopy. Alterations found: presence of concentric cell membrane fragments, larger number of primary and secondary lysossomes, vacuoles, and cytoplasmic vesicles, and an enlargement of the intercellular space and between the basolateral interdigitation of the choroid epithelium. The alterations observed are probably associated to an increase of the ventricular pressure, inducing morpho-functional effects on the choroid plexus integrity.

Ultrastructural study of the lateral ventricle choroid plexus in experimental hydrocephalus in Wistar rats

Hydrocephalus is one of the most frequent and complex neurological diseases characterized by the abnormal buildup of cerebrospinal fluid (CSF) in the ventricles of the brain, due to an altered CSF dynamics. To detect possible ultrastructural alterations of the lateral ventricles choroid plexus (responsible for the CSF production), rats seven days after birth were submitted to an intracisternal injection of 20 percent kaolim (hydrated aluminum silicate) for the hydrocephalus induction. Twenty-eight or 35 days after injection, injected animals and respective controls were processed for observation under a transmission electron microscopy. Alterations found: presence of concentric cell membrane fragments, larger number of primary and secondary lysossomes, vacuoles, and cytoplasmic vesicles, and an enlargement of the intercellular space and between the basolateral interdigitation of the choroid epithelium. The alterations observed are probably associated to an increase of the ventricular pressure, inducing morpho-functional effects on the choroid plexus integrity.

A hidrocefalia é uma das mais freqüentes e complexas doenças neurológicas caracterizada pelo acúmulo de líquido cefalorraquidiano (LCR) no interior dos ventrículos cerebrais e conseqüente alteração na dinâmica liquórica. Para detectar as possíveis alterações ultra-estruturais nos plexos corióides dos ventrículos laterais (responsáveis pela produção do LCR), ratos sete dias após o nascimento, foram submetidos à indução de hidrocefalia pela injeção intracisternal de caulim a 20 por cento. Após 28 e 35 dias da injeção, estes animais e seus respectivos controles foram processados para observação em um microscópio eletrônico de transmissão. Alterações observadas: presença de membranas concêntricas, maior número de lisossomos primários e secundários, vacúolos e vesículas citoplasmáticas, aumento do espaço intercelular e entre as interdigitações basolaterais das células do epitélio corióideo. As alterações observadas possivelmente estão associadas ao aumento da pressão nos ventrículos, induzindo efeitos morfo-funcionais na integridade dos plexos corióides.

A rat homologue of CED-6 is expressed in neurons and interacts with clathrin.

We isolated from a brain library a cDNA encoding an isoform of rat CED-6 that has not been previously described. This transcript results from alternative splicing of the ced-6 gene present on chromosome 9. We expressed this isoform as his-tagged protein in E. coli and used the purified protein to raise antibodies to investigate the expression of CED-6 in rat brain. Immunoblot analysis showed the presence of CED-6 as a doublet of approximately 34 and 33 kDa in cortex, hippocampus and cerebellum, indicating that the protein was present in different regions of the brain. Subcellular fractionation experiments showed that CED-6 immunoreactivity did not concentrate in GFAP-containing glial vesicles, whereas it showed a distribution similar to the synaptotagmin in synaptosomes-enriched fractions, suggesting that CED-6 is present in neurons. CED-6 immunoreactivity was also investigated using immunohistochemistry analysis and it was found in several brain regions, being particularly strong in the cell body of some groups of neurons such as Purkinje cell layer of cerebellum, and pyramidal cells of the hippocampal formation and also in epithelial cells from the choroid plexus. Importantly, CED-6 immunoreactivity colocalized with a neuronal marker but not with a glial marker. Considering that several PTB-containing proteins bind clathrin, we investigated whether rat CED-6 would also have this property. Yeast two-hybrid and GST pull-down analysis indicated that ratCED-6 interacts with clathrin and in cultured cells we detected colocalization between CED-6 and clathrin-coated vesicles. The present findings suggest that CED-6 may have a role in endocytic trafficking or signaling in neurons.

Scanning electron microscopy of the choroid plexus of the lateral ventricle of the horse.

The present study examined the ultrastructure of the choroid plexus of the lateral ventricle of the horse. The material was fixed in 2.5% glutaraldehyde in 0.1 m sodium phosphate buffer, pH 7.3, processed and analysed by scanning electron microscopy. The choroid plexus was characterized by regions with a predominance of villi, which resembled finger-like projections or bunches of grapes, and others where straight and uniform folds predominated. Epithelial cells projected into the ventricle and large amounts of cilia and microvilli were observed on their surface. The choroid glomus corresponded to a dilatation of the choroid plexus and was characterized by blood vessels of different calibres surrounded by connective tissue.

Effects of low-dose phenytoin administered to rats fetuses on developing choroid plexus: kariometric study

The aim of the present study was to determine, by kariometric parameters, the influence of phenytoin, as teratogen, on the epithelial layer of choroid plexus in rats fetuses, using single daily dose ( 75 mg Kg-1 bd.wt.), during gestation GD9 to GD11, and lowest total dose used orally (225 mg Kg-1), to the best of our knowledge. In some of experimental studies in animals, the anticonvulsant drug phenytoin were administered in embriotoxic daily doses (100-1500 mg Kg-1 bd.wt.) increasing concentrations up to 20 times the human therapeutic plasma concentration. There is a significant lack of information regarding the embriotoxicity in pregnancy of these drug, phenytoin, in low doses. Phenytoin was administered in a single daily dose (75 mg Kg-1 bd.wt.) to pregnanty rats in GD9 to GD11 days of gestation, during organogenesis. Histological sections were obtained for analysis of nuclear alterations in the cuboidal epithelium of choroid plexuses of lateral ventricles in the rat fetuses. Eleven kariometric parameters were measured in each of the nuclei. Statistical comparison were made with Mann-Whitney's test. The nuclei of the phenytoin group showed significant reduction of the size parameters : longest axis, mean axis, nuclear volume, nuclear area, nuclear perimeter, ratio of the longest axis to the shortest axis, ratio of the nuclear volume to the nucleararea) but not in shortest axis and shape parameters (contour index, shape factor and eccentricity) . A distinctive pattern of nuclear abnormalities in choroid plexus ephitelium of rat fetuses is associated with the use of low dose of phenytoin during pregnancy. Variations in nuclear size might reflect fundamental nuclear alterations of significance during the process of embriogenesis and could represent teratogenic influence of phenytoin in rats. Even at low dosage and short period of use during gestation, phenytoin can induce embriotoxicity.

Scanning electron microscopy study of the choroid plexus in the monkey (Cebus apella apella).

The cells of the choroid plexus of the lateral ventricles of the monkey Cebus apella apella were examined through scanning electron microscopy at contributing to the description of such structures in primates. The animals were anesthetized previously with 3% hypnol intraperitoneally and after perfusion with 2.5% glutaraldehyde, samples of the choroid plexus were collected after exhibition of the central portion and inferior horn of the lateral ventricles. The ventricular surface of those cells presents globose form as well as fine interlaced protrusions named microvilli. Among those, it is observed the presence of some cilia. Resting on the choroid epithelial cells there is a variable number of free cells, with fine prolongations which extend from them. They are probably macrophages and have been compared to Kolmer cells or epiplexus cells, located on choroid epithelium. The choroid plexus of the encephalic lateral ventricles of the monkey Cebus apella apella at scanning electron microscopy is similar to that of other primates, as well as to that of other species of mammals mainly cats and rats, and also humans.

Scanning electron microscopy study of the choroid plexus in the monkey (Cebus apella apella)

The cells of the choroid plexus of the lateral ventricles of the monkey Cebus apella apella were examined through scanning electron microscopy at contributing to the description of such structures in primates. The animals were anesthetized previously with 3 percent hypnol intraperitoneally and after perfusion with 2.5 percent glutaraldehyde, samples of the choroid plexus were collected after exhibition of the central portion and inferior horn of the lateral ventricles. The ventricular surface of those cells presents globose form as well as fine interlaced protrusions named microvilli. Among those, it is observed the presence of some cilia. Resting on the choroid epithelial cells there is a variable number of free cells, with fine prolongations which extend from them. They are probably macrophages and have been compared to Kolmer cells or epiplexus cells, located on choroid epithelium. The choroid plexus of the encephalic lateral ventricles of the monkey Cebus apella apella at scanning electron microscopy is similar to that of other primates, as well as to that of other species of mammals mainly cats and rats, and also humans

Ultrastructural alterations of choroid plexuses of lateral ventricles of rats (Rattus norvegicus) submitted to experimental chronic alcoholism.

Adult male rats (Wistar lineage) were alcoholized with sugar cane liquor diluted at 30(0) GL during 300 days and sacrificed every 60 days in 5 stages. Samples of choroid plexuses of lateral ventricles were collected and examined at transmission electronic microscope to detect possible ultrastructural alterations and to raise possible pathological correlations. Gradual changes were observed in these animals during all the experiment: dilatation and enlargement of cisternae of Golgi complex, dilatation of RER, presence of digestive vacuoles and a large amount of pinocytic vesicles as well as vesicles with electronlucent content throughout cytoplasm, as well as an enlargement of intercellular space between basolateral interdigitation of the cells and of the connective tissue. The changes observed in the epithelium and connective tissue of choroid plexuses specially in 240 and 300 days of treatment are presumably due to a disturbance in hydroelectrolitic homeostasis, contributing to several morpho-functional disturbs of central nervous system. No changes were observed in the control group animals.

Ultrastructural alterations of choroid plexuses of lateral ventricles of rats (Rattus norvegicus) submitted to experimental chronic alcoholism

Adult male rats (Wistar lineage) were alcoholized with sugar cane liquor diluted at 30(0) GL during 300 days and sacrificed every 60 days in 5 stages. Samples of choroid plexuses of lateral ventricles were collected and examined at transmission electronic microscope to detect possible ultrastructural alterations and to raise possible pathological correlations. Gradual changes were observed in these animals during all the experiment: dilatation and enlargement of cisternae of Golgi complex, dilatation of RER, presence of digestive vacuoles and a large amount of pinocytic vesicles as well as vesicles with electronlucent content throughout cytoplasm, as well as an enlargement of intercellular space between basolateral interdigitation of the cells and of the connective tissue. The changes observed in the epithelium and connective tissue of choroid plexuses specially in 240 and 300 days of treatment are presumably due to a disturbance in hydroelectrolitic homeostasis, contributing to several morpho-functional disturbs of central nervous system. No changes were observed in the control group animals.

Ultrastructural changes of the choroid plexus of the lateral ventricles of rats, rattus norvegicus, submitted to experimental chronic alcoholism, followed by alcohol withdrawal

Cuarenta ratas machos adultas se dividieron en dos grupos de 20 animales cada uno (grupos control y experimentales). El grupo experimental recibió alcohol de caña de azúcar comercial, marca "51 Pirassununga", diluida a 30º g/L como dieta líquida por un período de 240 días y agua potable por los siguientes 60 días. Los animales se sacrificaron después de 60, 120, 180, 240 y 300 días de tratamiento. Se observaron varios cambios morfológicos en el grupo experimental de animales de hasta 240 días de tratamiento, encontrándose dilatación de las cisternas del retículo endoplasmático rugoso, espacios intercelulares aumentados, espacios entre las interdigitaciones basolaterales de las células, inflamación del tejido conjuntivo y presencia de una gran cantidad de células pinocíticas, de vacuolas digestivas y de vesículas con contenido electrolúcido a lo largo del citoplasma. Después de 300 días de tratamiento, el grupo experimental de animales presentó una regresión importante de los cambios descritos. No se observó cambios en el grupo de animales control