How are some bacteria able to cross the blood-brain barrier?

How are some bacteria able to cross the blood-brain barrier?

Bacteria enter the central nervous system following a direct interaction with the luminal side of the cerebral endothelium, which constitutes the blood-brain barrier. To breach the barriers protecting the brain, extracellular pathogens must cross a monolayer of tight junction-expressing endothelial or epithelial cells.

What types of materials are able to cross the blood-brain barrier?

The blood–brain barrier restricts the passage of pathogens, the diffusion of solutes in the blood, and large or hydrophilic molecules into the cerebrospinal fluid, while allowing the diffusion of hydrophobic molecules (O2, CO2, hormones) and small non-polar molecules.

What is blood brain barrier permeability?

Limited permeability restricts movement of substances from the systemic circulation to the brain which buffers the brain from rapid changes in ionic or metabolic conditions. …

What is the blood brain barrier and what is its function?

The blood-brain barrier (BBB) is the specialized system of brain microvascular endothelial cells (BMVEC) that shields the brain from toxic substances in the blood, supplies brain tissues with nutrients, and filters harmful compounds from the brain back to the bloodstream.

Is blood brain barrier tight junctions?

The blood-brain barrier (BBB) is formed by the endothelial cells of cerebral microvessels, providing a dynamic interface between the peripheral circulation and the central nervous system. The tight junctions (TJs) between the endothelial cells serve to restrict blood-borne substances from entering the brain.

Why does the brain require an uninterrupted supply of blood?

Without a steady supply of oxygen, and to a lesser extent glucose, the nervous tissue in the brain cannot keep up its extensive electrical activity. These nutrients get into the brain through the blood, and if blood flow is interrupted, neurological function is compromised.

What protects the brain from foreign substances in the blood that might injure the brain?

The BBB has several important functions: Protects the brain from “foreign substances” in the blood that may injure the brain. Protects the brain from hormones and neurotransmitters in the rest of the body.

Does riluzole cross the blood-brain barrier?

Riluzole is the only available agent that alters the course of motor neuron disease. It crosses the blood–brain barrier and inhibits the release of glutamate, as well as acting as an antagonist at glutamate N-methyl-d-aspartate (NMDA) receptors on damaged neurons.