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 VOLUME Vol.05 Issue06 2025 

PAGE NO. 25-27 

DOI 10.37547/ajbspi/Volume05Issue06-06 

 
 
 
 

Blood-Brain Barrier: Structure, Function and 

Neurological Consequences Of Disruption: Role In Brain 

Protection And Maintenance Of Homeostasis. 

Disturbances In Strokes, Neuroinfections , 

Neurodegeneration , Tumors 
 

Petrova Yurita Yurievna 

Assistant Professor, Department of Biomedical Sciences, EMU University, Uzbekistan 

 

Received: 17 April 2025; Accepted: 24 May 2025; Published: 30 June 2025 

 

Abstract: The blood-brain barrier (BBB) is a complex morphofunctional system that ensures selective permeability 
between the bloodstream and tissues of the central nervous system. This article discusses the anatomical and 
histological structure of the BBB, its key functions in protecting the brain and maintaining neuronal homeostasis. 
Particular attention is paid to the mechanisms of barrier function impairment in various pathological conditions - 
strokes, neuroinfections , neurodegenerative diseases and brain tumors. The consequences of BBB dysfunction 
and modern approaches to diagnostics and therapy, including pharmacological modulation and targeted drug 
delivery technologies are analyzed. The presented material emphasizes the importance of maintaining the 
integrity of the BBB for neuroprotection and treatment of a wide range of neurological disorders. 

 

Keywords: Blood-brain barrier, neurohomeostasis , permeability, stroke, neuroinfections, neurodegenerative 
diseases, brain tumors, cerebral edema, tight junctions , neuroinflammation. 

 

Introduction: The human central nervous system (CNS) 
is highly sensitive to changes in the internal and 
external environment, which necessitates its reliable 
protection. One of the key structures that ensures the 
isolation of the brain from potentially harmful 
substances circulating in the systemic bloodstream is 
the blood-brain barrier (BBB). This unique structure, 
formed by tight junctions of endothelial cells of brain 
capillaries, pericytes, astrocytes and the basement 
membrane, acts as a selective filter and active regulator 
of exchange between blood and nervous tissue. 

The BBB not only prevents the penetration of toxins, 
pathogens and immune cells into the brain 
parenchyma, but also participates in maintaining ionic 
balance, nutrient delivery, and regulating 
neuroinflammatory reactions. Violation of the integrity 
and function of the BBB underlies the pathogenesis of 
a wide range of neurological diseases, including 
ischemic and hemorrhagic stroke, neuroinfections , 
multiple sclerosis, Alzheimer's disease and brain 

tumors. 

Modern concepts of the structure and functions of the 
BBB, as well as the mechanisms of its disruption, are 
important not only for diagnostics, but also for the 
development of new therapeutic approaches, including 
methods of targeted drug delivery to the central 
nervous system. The purpose of this article is to 
systematize existing data on the morphology and 
functions of the BBB, analyze the neurological 
consequences of its disruption, and consider promising 
areas in the restoration and modulation of the barrier 
function in various diseases. 

Purpose of the study 

To study the structure and functions of the blood-brain 
barrier and analyze the consequences of its disruption 
in various neurological diseases. 

Materials and methods 

The study used modern literature data, including 
experimental and clinical studies devoted to the 

 

https://doi.org/10.37547/ajbspi/Volume05Issue06-06
https://doi.org/10.37547/ajbspi/Volume05Issue06-06


American Journal of Applied Science and Technology 26 https://theusajournals.com/index.php/ajast 

American Journal of Applied Science and Technology (ISSN: 2771-2745) 
 

 

morphology, functions and disorders of the blood-brain 
barrier (BBB). The analysis was carried out on the basis 
of publications obtained from the scientific databases 
PubMed , Scopus , Web of Science over the past 10 
years. 

To illustrate the mechanisms of BBB disruption, the 
results of morphological and biochemical studies on 
animal models of stroke, neuroinfections and 
neurodegenerative diseases, as well as data from 
clinical observations of patients with similar 
pathologies are considered. 

Methods included studying the barrier structure using 
electron microscopy, immunohistochemical analysis of 
tight junctions ( tight junction proteins ), as well as 
assessment of functional permeability using contrast 
imaging techniques and inflammatory biomarkers . 

RESULTS AND DISCUSSION 

The analysis of literature and experimental data 
confirmed the complex and multi-level structure of the 
blood-brain barrier (BBB), which ensures its high 
selectivity and protective function. Endothelial cells 
with tight junctions ( claudin , occludin , ZO-1) form the 
main physical barrier, supported by astrocytic 
endothelial cells and pericytes. Violation of the 
integrity of these components leads to increased 
permeability of the BBB and the development of 
neurological complications. 

Strokes are associated with significant weakening of 
tight junctions and activation of matrix 
metalloproteinases (MMP-9), which is accompanied by 
vasogenic edema and increased inflammation. These 
processes contribute to secondary damage to brain 
tissue and worsen the prognosis. Similarly, in 
neuroinfections , pathogens and inflammatory 
mediators destroy the barrier, facilitating access for 
immune cells, but simultaneously increasing the risk of 
edema and neuronal damage. 

In neurodegenerative diseases such as Alzheimer's 
disease and multiple sclerosis, BBB dysfunction is 
associated with impaired β-amyloid transport, 
increased neuroinflammation , and lymphocyte 
infiltration into the CNS, which accelerates disease 
progression. 

Tumor growth, especially in glioblastomas , is 
accompanied by the secretion of factors that destroy 
the barrier and cause vasogenic edema, which 
complicates treatment and worsens the quality of life 
of patients. 

Modern diagnostic methods, including contrast MRI 
and inflammation biomarkers , allow for timely 
detection of BBB disruptions. Therapeutic strategies 
aimed at barrier stabilization, MMP inhibition, and 

targeted drug delivery through temporary BBB opening 
show promise for improving clinical outcomes. 

Thus, maintaining the integrity of the BBB is critical for 
neuroprotection and effective treatment of many CNS 
diseases. 

CONCLUSION 

The blood-brain barrier is a key element of brain 
protection, ensuring selective transport of substances 
and maintaining homeostasis of the central nervous 
system. Disruptions in the integrity and function of the 
BBB play an important role in the pathogenesis of many 
neurological diseases, including strokes, 
neuroinfections, neurodegenerative processes and 
brain tumors. Understanding the mechanisms of 
barrier disruption opens up new opportunities for 
diagnostics and the development of effective 
therapeutic approaches aimed at restoring and 
modulating its function. Further research in this area 
will contribute to improving the treatment and 
prevention of neurological disorders. 

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