Barrier function in the peripheral and central nervous system-a review.

Area of Science:

• Neuroscience
• Cell Biology
• Physiology

Background:

• The central nervous system (CNS) and peripheral nervous system (PNS) are vital structures requiring protection from harmful stimuli.
• Specialized barriers, including the blood-brain barrier (BBB), blood-nerve barrier (BNB), and blood-spinal cord barrier (BSCB), safeguard these systems.

Purpose of the Study:

• To detail the anatomy and function of neural barriers (BNB, BBB, BSCB).
• To identify key tight junction (TJ) proteins crucial for nervous system barrier integrity.
• To explore the role of barrier dysfunction in neurological diseases and its impact on drug delivery.

Main Methods:

• Review of anatomical and functional aspects of neural barriers.
• Identification and description of relevant tight junction proteins (e.g., claudins, occludin, ZO-1, tricellulin).
• Analysis of the impact of diseases on barrier permeability and function.

Main Results:

• Identified claudin-1, -3, -5, -11, -12, -19, occludin, ZO-1, and tricellulin as key TJ proteins in neural barriers.
• Demonstrated that barrier disruption exacerbates conditions like peripheral nerve injury, inflammatory polyneuropathy, ALS, MS, spinal cord injury, and Alzheimer's disease.
• Highlighted that intact barriers impede drug delivery for neurodegenerative diseases and inflammatory pain.

Conclusions:

• Neural barrier dysfunction is a significant factor in the pathogenesis and progression of various neurological disorders.
• Understanding barrier regulation offers potential for developing novel therapeutics to modulate barrier function for treating neurological diseases.
• Targeting neural barriers could enhance drug delivery, improving treatment efficacy for CNS and PNS conditions.