scholarly journals 24. The Electron Microscopic Studies on the Brain Cortex during Infusion of Hypotonic- and Hypertonic Glucose Solution, Especially in Relation to the Blood-Brain Barrier

1962 ◽  
Vol 4 (0) ◽  
pp. 162-163
Author(s):  
Junichi WAKIZAKA ◽  
Shinken KURAMOTO ◽  
Toshikazu FUKUDA
Keyword(s):  
Blood Brain Barrier ◽  
Brain Cortex ◽  
Glucose Solution ◽  
Brain Barrier ◽  
Electron Microscopic ◽  
Hypertonic Glucose ◽  
Blood Brain ◽  
Microscopic Studies ◽  
The Brain

Experimental Disruption of the Blood-Brain Barrier System in an Insect (Periplaneta Americana)

1973 ◽  
Vol 59 (3) ◽  
pp. 711-724
Author(s):  
J. E. TREHERNE
Keyword(s):  
Blood Brain Barrier ◽  
Periplaneta Americana ◽  
Brain Barrier ◽  
Ultrastructural Changes ◽  
Hypertonic Solution ◽  
Electron Microscopic ◽  
Blood Brain ◽  
Ionic Lanthanum ◽  
Electrophysiological Studies ◽  
Microscopic Studies

1. The effects of hypertonic urea and hypertonic glucose solutions upon the ‘blood-brain barrier’ in the isolated abdominal nerve cord of the cockroach have been studied. 2. Electrophysiological studies showed that a hypertonic solution of urea, but not of glucose, was effective in reducing the barrier to the entry of potassium and the loss of sodium. 3. Electron-microscopic studies revealed no significant ultrastructural changes, and no disruption of the perineurial barrier to the entry of ionic lanthanum, following comparable exposure to the hypertonic solutions. 4. It is suggested that this alteration of the blood-brain barrier may result from a selective change in permeability of the perineurial membranes or tight junctions.

Ligand and Structure-based Modeling of Passive Diffusion through the Blood-Brain Barrier

2018 ◽  
Vol 25 (9) ◽  
pp. 1073-1089 ◽  
Author(s):  
Santiago Vilar ◽  
Eduardo Sobarzo-Sanchez ◽  
Lourdes Santana ◽  
Eugenio Uriarte
Keyword(s):  
Blood Brain Barrier ◽  
In Silico ◽  
Passive Diffusion ◽  
Brain Barrier ◽  
Barrier Permeability ◽  
Blood Brain Barrier Permeability ◽  
Blood Brain ◽  
Brain Barrier Permeability ◽  
Different Types ◽  
The Brain

Background: Blood-brain barrier transport is an important process to be considered in drug candidates. The blood-brain barrier protects the brain from toxicological agents and, therefore, also establishes a restrictive mechanism for the delivery of drugs into the brain. Although there are different and complex mechanisms implicated in drug transport, in this review we focused on the prediction of passive diffusion through the blood-brain barrier. Methods: We elaborated on ligand-based and structure-based models that have been described to predict the blood-brain barrier permeability. Results: Multiple 2D and 3D QSPR/QSAR models and integrative approaches have been published to establish quantitative and qualitative relationships with the blood-brain barrier permeability. We explained different types of descriptors that correlate with passive diffusion along with data analysis methods. Moreover, we discussed the applicability of other types of molecular structure-based simulations, such as molecular dynamics, and their implications in the prediction of passive diffusion. Challenges and limitations of experimental measurements of permeability and in silico predictive methods were also described. Conclusion: Improvements in the prediction of blood-brain barrier permeability from different types of in silico models are crucial to optimize the process of Central Nervous System drug discovery and development.

Liposomes: Novel Drug Delivery Approach for Targeting Parkinson’s Disease

2020 ◽  
Vol 26 (37) ◽  
pp. 4721-4737 ◽  
Author(s):  
Bhumika Kumar ◽  
Mukesh Pandey ◽  
Faheem H. Pottoo ◽  
Faizana Fayaz ◽  
Anjali Sharma ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Drug Delivery ◽  
Parkinson's Disease ◽  
Side Effects ◽  
Blood Brain Barrier ◽  
Brain Barrier ◽  
Brain Targeting ◽  
Neural Cells ◽  
Blood Brain ◽  
The Brain

Parkinson’s disease is one of the most severe progressive neurodegenerative disorders, having a mortifying effect on the health of millions of people around the globe. The neural cells producing dopamine in the substantia nigra of the brain die out. This leads to symptoms like hypokinesia, rigidity, bradykinesia, and rest tremor. Parkinsonism cannot be cured, but the symptoms can be reduced with the intervention of medicinal drugs, surgical treatments, and physical therapies. Delivering drugs to the brain for treating Parkinson’s disease is very challenging. The blood-brain barrier acts as a highly selective semi-permeable barrier, which refrains the drug from reaching the brain. Conventional drug delivery systems used for Parkinson’s disease do not readily cross the blood barrier and further lead to several side-effects. Recent advancements in drug delivery technologies have facilitated drug delivery to the brain without flooding the bloodstream and by directly targeting the neurons. In the era of Nanotherapeutics, liposomes are an efficient drug delivery option for brain targeting. Liposomes facilitate the passage of drugs across the blood-brain barrier, enhances the efficacy of the drugs, and minimize the side effects related to it. The review aims at providing a broad updated view of the liposomes, which can be used for targeting Parkinson’s disease.

Brain Drug Delivery: Overcoming the Blood-brain Barrier to Treat Tauopathies

2020 ◽  
Vol 26 (13) ◽  
pp. 1448-1465 ◽  
Author(s):  
Jozef Hanes ◽  
Eva Dobakova ◽  
Petra Majerova
Keyword(s):  
Drug Delivery ◽  
Blood Brain Barrier ◽  
Neurodegenerative Disorders ◽  
Brain Barrier ◽  
Neuronal Function ◽  
Brain Drug Delivery ◽  
Naturally Occurring ◽  
Blood Brain ◽  
Traditional Approaches ◽  
The Brain

Tauopathies are neurodegenerative disorders characterized by the deposition of abnormal tau protein in the brain. The application of potentially effective therapeutics for their successful treatment is hampered by the presence of a naturally occurring brain protection layer called the blood-brain barrier (BBB). BBB represents one of the biggest challenges in the development of therapeutics for central nervous system (CNS) disorders, where sufficient BBB penetration is inevitable. BBB is a heavily restricting barrier regulating the movement of molecules, ions, and cells between the blood and the CNS to secure proper neuronal function and protect the CNS from dangerous substances and processes. Yet, these natural functions possessed by BBB represent a great hurdle for brain drug delivery. This review is concentrated on summarizing the available methods and approaches for effective therapeutics’ delivery through the BBB to treat neurodegenerative disorders with a focus on tauopathies. It describes the traditional approaches but also new nanotechnology strategies emerging with advanced medical techniques. Their limitations and benefits are discussed.

scholarly journals Miniaturization and Automation of a Human In Vitro Blood–Brain Barrier Model for the High-Throughput Screening of Compounds in the Early Stage of Drug Discovery

Pharmaceutics ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 892
Author(s):  
Elisa L. J. Moya ◽  
Elodie Vandenhaute ◽  
Eleonora Rizzi ◽  
Marie-Christine Boucau ◽  
Johan Hachani ◽  
...  
Keyword(s):  
Drug Discovery ◽  
Blood Brain Barrier ◽  
Early Stage ◽  
Molecular Transport ◽  
Brain Barrier ◽  
Blood Brain ◽  
Cns Drugs ◽  
The Impact ◽  
The Brain

Central nervous system (CNS) diseases are one of the top causes of death worldwide. As there is a difficulty of drug penetration into the brain due to the blood–brain barrier (BBB), many CNS drugs treatments fail in clinical trials. Hence, there is a need to develop effective CNS drugs following strategies for delivery to the brain by better selecting them as early as possible during the drug discovery process. The use of in vitro BBB models has proved useful to evaluate the impact of drugs/compounds toxicity, BBB permeation rates and molecular transport mechanisms within the brain cells in academic research and early-stage drug discovery. However, these studies that require biological material (animal brain or human cells) are time-consuming and involve costly amounts of materials and plastic wastes due to the format of the models. Hence, to adapt to the high yields needed in early-stage drug discoveries for compound screenings, a patented well-established human in vitro BBB model was miniaturized and automated into a 96-well format. This replicate met all the BBB model reliability criteria to get predictive results, allowing a significant reduction in biological materials, waste and a higher screening capacity for being extensively used during early-stage drug discovery studies.

scholarly journals Probable Causes of Alzheimer’s Disease

Sci ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 16
Author(s):  
James David Adams
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Lactic Acid ◽  
Blood Brain Barrier ◽  
Transient Receptor Potential ◽  
Brain Barrier ◽  
Folate Intake ◽  
Blood Brain ◽  
Age Related ◽  
The Brain

A three-part mechanism is proposed for the induction of Alzheimer’s disease: (1) decreased blood lactic acid; (2) increased blood ceramide and adipokines; (3) decreased blood folic acid. The age-related nature of these mechanisms comes from age-associated decreased muscle mass, increased visceral fat and changes in diet. This mechanism also explains why many people do not develop Alzheimer’s disease. Simple changes in lifestyle and diet can prevent Alzheimer’s disease. Alzheimer’s disease is caused by a cascade of events that culminates in damage to the blood–brain barrier and damage to neurons. The blood–brain barrier keeps toxic molecules out of the brain and retains essential molecules in the brain. Lactic acid is a nutrient to the brain and is produced by exercise. Damage to endothelial cells and pericytes by inadequate lactic acid leads to blood–brain barrier damage and brain damage. Inadequate folate intake and oxidative stress induced by activation of transient receptor potential cation channels and endothelial nitric oxide synthase damage the blood–brain barrier. NAD depletion due to inadequate intake of nicotinamide and alterations in the kynurenine pathway damages neurons. Changes in microRNA levels may be the terminal events that cause neuronal death leading to Alzheimer’s disease. A new mechanism of Alzheimer’s disease induction is presented involving lactic acid, ceramide, IL-1β, tumor necrosis factor α, folate, nicotinamide, kynurenine metabolites and microRNA.

scholarly journals Pharmacokinetics and Molecular Modeling Indicate nAChRα4-Derived Peptide HAEE Goes through the Blood–Brain Barrier

Biomolecules ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 909
Author(s):  
Yurii A. Zolotarev ◽  
Vladimir A. Mitkevich ◽  
Stanislav I. Shram ◽  
Alexei A. Adzhubei ◽  
Anna P. Tolstova ◽  
...  
Keyword(s):  
Molecular Modeling ◽  
Mouse Model ◽  
Blood Brain Barrier ◽  
Brain Barrier ◽  
Laboratory Animals ◽  
Pharmacokinetic Parameters ◽  
Pharmacokinetic Data ◽  
Bolus Administration ◽  
Blood Brain ◽  
The Brain

One of the treatment strategies for Alzheimer’s disease (AD) is based on the use of pharmacological agents capable of binding to beta-amyloid (Aβ) and blocking its aggregation in the brain. Previously, we found that intravenous administration of the synthetic tetrapeptide Acetyl-His-Ala-Glu-Glu-Amide (HAEE), which is an analogue of the 35–38 region of the α4 subunit of α4β2 nicotinic acetylcholine receptor and specifically binds to the 11–14 site of Aβ, reduced the development of cerebral amyloidogenesis in a mouse model of AD. In the current study on three types of laboratory animals, we determined the biodistribution and tissue localization patterns of HAEE peptide after single intravenous bolus administration. The pharmacokinetic parameters of HAEE were established using uniformly tritium-labeled HAEE. Pharmacokinetic data provided evidence that HAEE goes through the blood–brain barrier. Based on molecular modeling, a role of LRP1 in receptor-mediated transcytosis of HAEE was proposed. Altogether, the results obtained indicate that the anti-amyloid effect of HAEE, previously found in a mouse model of AD, most likely occurs due to its interaction with Aβ species directly in the brain.

scholarly journals Trojan Horse Transit Contributes to Blood-Brain Barrier Crossing of a Eukaryotic Pathogen

mBio ◽  
2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Felipe H. Santiago-Tirado ◽  
Michael D. Onken ◽  
John A. Cooper ◽  
Robyn S. Klein ◽  
Tamara L. Doering
Keyword(s):  
Experimental Evidence ◽  
Cryptococcus Neoformans ◽  
Blood Brain Barrier ◽  
Fungal Pathogen ◽  
Trojan Horse ◽  
Brain Barrier ◽  
Barrier Crossing ◽  
Blood Brain ◽  
The Brain

ABSTRACT The blood-brain barrier (BBB) protects the central nervous system (CNS) by restricting the passage of molecules and microorganisms. Despite this barrier, however, the fungal pathogen Cryptococcus neoformans invades the brain, causing a meningoencephalitis that is estimated to kill over 600,000 people annually. Cryptococcal infection begins in the lung, and experimental evidence suggests that host phagocytes play a role in subsequent dissemination, although this role remains ill defined. Additionally, the disparate experimental approaches that have been used to probe various potential routes of BBB transit make it impossible to assess their relative contributions, confounding any integrated understanding of cryptococcal brain entry. Here we used an in vitro model BBB to show that a “Trojan horse” mechanism contributes significantly to fungal barrier crossing and that host factors regulate this process independently of free fungal transit. We also, for the first time, directly imaged C. neoformans-containing phagocytes crossing the BBB, showing that they do so via transendothelial pores. Finally, we found that Trojan horse crossing enables CNS entry of fungal mutants that cannot otherwise traverse the BBB, and we demonstrate additional intercellular interactions that may contribute to brain entry. Our work elucidates the mechanism of cryptococcal brain invasion and offers approaches to study other neuropathogens. IMPORTANCE The fungal pathogen Cryptococcus neoformans invades the brain, causing a meningoencephalitis that kills hundreds of thousands of people each year. One route that has been proposed for this brain entry is a Trojan horse mechanism, whereby the fungus crosses the blood-brain barrier (BBB) as a passenger inside host phagocytes. Although indirect experimental evidence supports this intriguing mechanism, it has never been directly visualized. Here we directly image Trojan horse transit and show that it is regulated independently of free fungal entry, contributes to cryptococcal BBB crossing, and allows mutant fungi that cannot enter alone to invade the brain. IMPORTANCE The fungal pathogen Cryptococcus neoformans invades the brain, causing a meningoencephalitis that kills hundreds of thousands of people each year. One route that has been proposed for this brain entry is a Trojan horse mechanism, whereby the fungus crosses the blood-brain barrier (BBB) as a passenger inside host phagocytes. Although indirect experimental evidence supports this intriguing mechanism, it has never been directly visualized. Here we directly image Trojan horse transit and show that it is regulated independently of free fungal entry, contributes to cryptococcal BBB crossing, and allows mutant fungi that cannot enter alone to invade the brain.

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