The Existence of a Barrier Between the Cerebrospinal Fluid and the Boundary of the Brain; Including Experimental Investigations on Rabbits, Using Bilirubinaemia

SummaryBlood was injected into the brains of dogs to produce artificial haematomas, and paraffin injected to produce intracerebral paraffin masses. Cerebrospinal fluid (CSF) and peripheral blood samples were withdrawn at regular intervals and their fibrinolytic activities estimated by the fibrin plate method. Trans-form aminomethylcyclohexane-carboxylic acid (t-AMCHA) was administered to some individuals. Genera] relationships were found between changes in CSF fibrinolytic activity, area of tissue damage and survival time. t-AMCHA was clearly beneficial to those animals given a programme of administration. Tissue activator was extracted from the brain tissue after death or sacrifice for haematoma examination. The possible role of tissue activator in relation to haematoma development, and clinical implications of the results, are discussed.

Download Full-text

Vasopressin enhances the clearance of β-endorphin immunoreactivity from rat cerebrospinal fluid

Acta Endocrinologica ◽

10.1530/acta.0.1220191 ◽

1990 ◽

Vol 122 (2) ◽

pp. 191-200 ◽

Cited By ~ 7

Author(s):

C. G. J. Sweep ◽

Margreet D. Boomkamp ◽

István Barna ◽

A. Willeke Logtenberg ◽

Victor M. Wiegant

Keyword(s):

Cerebrospinal Fluid ◽

Receptor Antagonist ◽

Short Duration ◽

Lateral Ventricle ◽

Underlying Mechanism ◽

Terminal Phase ◽

Intracerebroventricular Injection ◽

Intracerebroventricular Administration ◽

Biphasic Pattern ◽

The Brain

Abstract The effect of intracerebroventricular (lateral ventricle) administration of arginine8-vasopressin (AVP) on the concentration of β-endorphin immunoreactivity in the cerebrospinal fluid obtained from the cisterna magna was studied in rats. A decrease was observed 5 min following injection of 0.9 fmol AVP. No statistically significant changes were found 5 min after intracerebroventricular treatment of rats with 0.09 or 9 fmol. The decrease induced by 0.9 fmol AVP was of short duration and was found 5 min after treatment but not 10 and 20 min. Desglycinamide9-AVP (0.97 fmol), [pGlu4, Cyt6]-AVP-(4–9) (1.44 fmol), Nα-acetyl-AVP (0.88 fmol), lysine8-vasopressin (0.94 fmol) and oxytocin (1 fmol) when intracerebroventricularly injected did not affect the levels of β-endorphin immunoreactivity in the cerebrospinal fluid 5 min later. This suggests that the intact AVP-(1–9) molecule is required for this effect. Intracerebroventricular pretreatment of rats with the vasopressin V1-receptor antagonist d(CH2)5Tyr(Me)AVP (8.63 fmol) completely blocked the effect of AVP (0.9 fmol). In order to investigate further the underlying mechanism, the effect of AVP on the disappearance from the cerebrospinal fluid of exogenously applied β-endorphin was determined. Following intracerebroventricular injection of 1.46 pmol camel β-endorphin-(1–31), the β-endorphin immunoreactivity levels in the cisternal cerebrospinal fluid increased rapidly, and reached peak values at 10 min. The disappearance of β-endorphin immunoreactivity from the cerebrospinal fluid then followed a biphasic pattern with calculated half-lifes of 28 and 131 min for the initial and the terminal phase, respectively. Treatment of rats with AVP (0.9 fmol; icv) during either phase (10, 30, 55 min following intracerebroventricular administration of 1.46 pmol β-endorphin-(1–31)) significantly enhanced the disappearance of β-endorphin immunoreactivity from the cerebrospinal fluid. The data suggest that vasopressin plays a role in the regulation of β-endorphin levels in the cerebrospinal fluid by modulating clearance mechanisms via V1-receptors in the brain.

Download Full-text

Spatially Organized Ciliary Beating Compartmentalizes Cerebrospinal Fluid Flow in the Brain and Regulates Ventricular Development

SSRN Electronic Journal ◽

10.2139/ssrn.3199994 ◽

2018 ◽

Cited By ~ 1

Author(s):

Emilie W. Olstad ◽

Christa Ringers ◽

Adinda Wens ◽

Jan N. Hansen ◽

Cecilia Brandt ◽

...

Keyword(s):

Cerebrospinal Fluid ◽

Fluid Flow ◽

Cerebrospinal Fluid Flow ◽

Ciliary Beating ◽

The Brain

Download Full-text

Cerebrospinal fluid γ-aminobutyric acid levels in dogs with chronic portosystemic encephalopathy

Clinical Science ◽

10.1042/cs0710749 ◽

1986 ◽

Vol 71 (6) ◽

pp. 749-753 ◽

Cited By ~ 9

Author(s):

J. E. Maddison ◽

D. Yau ◽

P. Stewart ◽

G. C. Farrell

Keyword(s):

Cerebrospinal Fluid ◽

Aminobutyric Acid ◽

Plasma Ammonia ◽

Portosystemic Encephalopathy ◽

Dog Model ◽

Csf Levels ◽

Neurological Features ◽

The Brain ◽

Biochemical Abnormalities

1. Cerebrospinal fluid (CSF) γ-aminobutyric acid (GABA) levels were measured in a dog model of spontaneous chronic portosystemic encephalopathy. 2. Dogs with congenital portacaval shunts (intra- or extra-hepatic) develop neurological features of abnormal psychomotor behaviour and depressed consciousness that are consistent with the symptoms of chronic portosystemic encephalopathy in humans. In the five dogs studied, plasma ammonia was elevated, as was CSF tryptophan, both usual biochemical abnormalities in portosystemic encephalopathy. 3. CSF levels of GABA in five dogs with portosystemic encephalopathy (100 ± 13 pmol/ml) were not significantly different from those in five control dogs (96 ± 14 pmol/ml). CSF levels of GABA were not altered after ammonia infusion. 4. If enhanced GABA-ergic neurotransmission, due to influx of gut-derived GABA into the brain, is responsible for the pathophysiology of chronic portosystemic encephalopathy in this model, it is not reflected by increased levels of GABA in CSF.

Download Full-text

Transfer of rhodamine-123 into the brain and cerebrospinal fluid of fetal, neonatal and adult rats

Fluids and Barriers of the CNS ◽

10.1186/s12987-021-00241-8 ◽

2021 ◽

Vol 18 (1) ◽

Author(s):

Liam M. Koehn ◽

Katarzyna M. Dziegielewska ◽

Mark D. Habgood ◽

Yifan Huang ◽

Norman R. Saunders

Keyword(s):

Cerebrospinal Fluid ◽

Fetal Brain ◽

Maternal Blood ◽

Adult Brain ◽

Rhodamine 123 ◽

Patient Specific ◽

Adult Rats ◽

Blood Brain ◽

The Brain ◽

Brain Barriers

Abstract Background Adenosine triphosphate binding cassette transporters such as P-glycoprotein (PGP) play an important role in drug pharmacokinetics by actively effluxing their substrates at barrier interfaces, including the blood-brain, blood-cerebrospinal fluid (CSF) and placental barriers. For a molecule to access the brain during fetal stages it must bypass efflux transporters at both the placental barrier and brain barriers themselves. Following birth, placental protection is no longer present and brain barriers remain the major line of defense. Understanding developmental differences that exist in the transfer of PGP substrates into the brain is important for ensuring that medication regimes are safe and appropriate for all patients. Methods In the present study PGP substrate rhodamine-123 (R123) was injected intraperitoneally into E19 dams, postnatal (P4, P14) and adult rats. Naturally fluorescent properties of R123 were utilized to measure its concentration in blood-plasma, CSF and brain by spectrofluorimetry (Clariostar). Statistical differences in R123 transfer (concentration ratios between tissue and plasma ratios) were determined using Kruskal-Wallis tests with Dunn’s corrections. Results Following maternal injection the transfer of R123 across the E19 placenta from maternal blood to fetal blood was around 20 %. Of the R123 that reached fetal circulation 43 % transferred into brain and 38 % into CSF. The transfer of R123 from blood to brain and CSF was lower in postnatal pups and decreased with age (brain: 43 % at P4, 22 % at P14 and 9 % in adults; CSF: 8 % at P4, 8 % at P14 and 1 % in adults). Transfer from maternal blood across placental and brain barriers into fetal brain was approximately 9 %, similar to the transfer across adult blood-brain barriers (also 9 %). Following birth when placental protection was no longer present, transfer of R123 from blood into the newborn brain was significantly higher than into adult brain (3 fold, p < 0.05). Conclusions Administration of a PGP substrate to infant rats resulted in a higher transfer into the brain than equivalent doses at later stages of life or equivalent maternal doses during gestation. Toxicological testing of PGP substrate drugs should consider the possibility of these patient specific differences in safety analysis.

Download Full-text

The orthopedic characterization of cfap298tm304 mutants validate zebrafish to faithfully model human AIS

Scientific Reports ◽

10.1038/s41598-021-86856-1 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Marie-Hardy Laura ◽

Cantaut-Belarif Yasmine ◽

Pietton Raphaël ◽

Slimani Lotfi ◽

Pascal-Moussellard Hugues

Keyword(s):

Cerebrospinal Fluid ◽

Three Dimensional ◽

Fluid Circulation ◽

Micro Computed Tomography ◽

Csf Flow ◽

Cerebrospinal Fluid Circulation ◽

Clinical Criteria ◽

Brain And Spinal Cord ◽

The Brain

AbstractCerebrospinal fluid (CSF) circulation relies on the beating of motile cilia projecting in the lumen of the brain and spinal cord cavities Mutations in genes involved in cilia motility disturb cerebrospinal fluid circulation and result in scoliosis-like deformities of the spine in juvenile zebrafish. However, these defects in spine alignment have not been validated with clinical criteria used to diagnose adolescent idiopathic scoliosis (AIS). The aim of this study was to describe, using orthopaedic criteria the spinal deformities of a zebrafish mutant model of AIS targeting a gene involved in cilia polarity and motility, cfap298tm304. The zebrafish mutant line cfap298tm304, exhibiting alteration of CSF flow due to defective cilia motility, was raised to the juvenile stage. The analysis of mutant animals was based on micro-computed tomography (micro-CT), which was conducted in a QUANTUM FX CALIPER, with a 59 µm-30 mm protocol. 63% of the cfap298tm304 zebrafish analyzed presented a three-dimensional deformity of the spine, that was evolutive during the juvenile phase, more frequent in females, with a right convexity, a rotational component and involving at least one dislocation. We confirm here that cfap298tm304 scoliotic individuals display a typical AIS phenotype, with orthopedic criteria mirroring patient’s diagnosis.

Download Full-text

Shear-Induced Amyloid Aggregation in the Brain: V. Are Alzheimer’s and Other Amyloid Diseases Initiated in the Lower Brain and Brainstem by Cerebrospinal Fluid Flow Stresses?

Journal of Alzheimer s Disease ◽

10.3233/jad-201025 ◽

2020 ◽

pp. 1-24

Author(s):

Conrad N. Trumbore

Keyword(s):

Cerebrospinal Fluid ◽

Conformational Changes ◽

Extensional Flow ◽

Amyloid Β ◽

High Energy ◽

Mechanical Agitation ◽

Cerebrospinal Fluid Flow ◽

Pulse Waves ◽

Amyloid Diseases ◽

The Brain

Amyloid-β (Aβ) and tau oligomers have been identified as neurotoxic agents responsible for causing Alzheimer’s disease (AD). Clinical trials using Aβ and tau as targets have failed, giving rise to calls for new research approaches to combat AD. This paper provides such an approach. Most basic AD research has involved quiescent Aβ and tau solutions. However, studies involving laminar and extensional flow of proteins have demonstrated that mechanical agitation of proteins induces or accelerates protein aggregation. Recent MRI brain studies have revealed high energy, chaotic motion of cerebrospinal fluid (CSF) in lower brain and brainstem regions. These and studies showing CSF flow within the brain have shown that there are two energetic hot spots. These are within the third and fourth brain ventricles and in the neighborhood of the circle of Willis blood vessel region. These two regions are also the same locations as those of the earliest Aβ and tau AD pathology. In this paper, it is proposed that cardiac systolic pulse waves that emanate from the major brain arteries in the lower brain and brainstem regions and whose pulse waves drive CSF flows within the brain are responsible for initiating AD and possibly other amyloid diseases. It is further proposed that the triggering of these diseases comes about because of the strengthening of systolic pulses due to major artery hardening that generates intense CSF extensional flow stress. Such stress provides the activation energy needed to induce conformational changes of both Aβ and tau within the lower brain and brainstem region, producing unique neurotoxic oligomer molecule conformations that induce AD.

Download Full-text

Cerebrospinal fluid homocysteine and the cobalamin status of the brain

Journal of Inherited Metabolic Disease ◽

10.1007/bf00711669 ◽

1993 ◽

Vol 16 (3) ◽

pp. 517-519 ◽

Cited By ~ 7

Author(s):

H. J. Blom ◽

R. A. Wevers ◽

A. Verrips ◽

M. T. W. B. TePoele-Pothoff ◽

J. M. F. Trijbels

Keyword(s):

Cerebrospinal Fluid ◽

The Brain

Download Full-text

Experimental intracerebral and subarachnoid/intraventricular haemorrhages: MR detectability at 0.5 T and 1.5 T

Acta Radiologica ◽

10.1258/rsmacta.43.5.464 ◽

2002 ◽

Vol 43 (5) ◽

pp. 464-473

Author(s):

M. Alemany Ripoll ◽

R. Raininko

Keyword(s):

Cerebrospinal Fluid ◽

Mr Imaging ◽

Spin Echo ◽

Autologous Blood ◽

Pulse Sequences ◽

Proton Density ◽

Gradient Echo ◽

The Brain ◽

Formalin Fixed

Purpose: To compare the detectability of small experimental intracranial haemorrhages on MR imaging at 0.5 T and 1.5 T, from hyperacute to subacute stages. Material and Methods: 1 ml of autologous blood was injected into the brain of 15 rabbits to create intraparenchymal haematomas. Since the blood partially escaped into the cerebrospinal fluid (CSF) spaces, detectability of subarachnoid and intraventricular blood was also evaluated. MR imaging at 0.5 T and at 1.5 T was repeated up to 14 days, including T1-, proton density- and T2-weighted (w) spin-echo (SE), FLAIR and T2*-w gradient echo (GE) pulse sequences. The last MR investigation was compared to the formalin-fixed brain sections in 7 animals. Results: The intraparenchymal haematomas were best revealed with T2*-w GE sequences, with 100% of sensitivity at 1.5 T and 90–95% at 0.5 T. Blood in the CSF spaces was significantly ( p < 0.05) better detected at 1.5 T with T2*-w GE sequences and detected best during the first 2 days. The next most sensitive sequence for intracranial blood was FLAIR. SE sequences were rather insensitive. Conclusion: 1.5 T equipment is superior to 0.5 T in the detection of intracranial haemorrhages from acute to subacute stages. T2*-w GE sequences account for this result but other sequences are also needed for a complete examination.

Download Full-text