Blood-Brain-Barrier Flashcards
(15 cards)
For which kind of particles is the BBB a selective barrier between blood and CNS ?
- Pathogens
- Proteins
- Leukocytes
- Large molecules
- Hydrophilic molecules
For which kind of particles is the BBB a gateway between blood and CNS ?
- Hormones
- Small, lipophilic, uncharged molecules
- Nutrients
Name the seven circumventricular organs.
- Area postrema
- Median eminence
- Pineal gland
- Choroid plexus
- Subfornical organ
- Vascular organ of lamina terminalis
- Posterior pituitary
What is characteristic for circumventricular organs ?
- They have extensive vasculature and fenestated capillaries
- they lead to a “leaky” BBB
What are the differences between peripheral and cerebral capillaries ?
- Peripheral capillaries:
- Are fenestrated
- Have a lower transcytotic rate
- Lower barrier: ~30Ω/cm^2 - Cerebral capillaries:
- Have a higher transcytotic rate
- Higher barrier: ~1500-2000Ω/cm^2
Name the four central players of a neurovascular unit.
- Endothelial cells
- Pericytes/Smooth muscle cells
- Astrocytes
- Neurons
Where can the pericytes be found ?
- Between the endothelial and the parenchymal basement membrane
- They surround the endothelial cell layer
What are the astrocytes essential for ?
For the water and ion homeostasis in the brain
Where can the astrocytes be found ?
- Between vessels, neurons and synapses
- They direct the contact
What are the main functions of endothelial cells ?
- Binding and regulation of immune cells
- Transport of essential molecules into the brain
- Build up of the BBB
Which four particles are needed for the formation of tight junctions ?
- Claudings
- Occludin
- Adaptor proteins
- Junctional adhesion molecules
What can happen if the BBB has an increased leakage ?
- Accumulation of neurotoxic serum proteins
- Accululation of iron which leads to ROS production
- Antibodies could lead to autoimmune diseases
- Neuronal cell loss and dysfunction
Name four diseases linked to BBB dysfunction.
- Stroke
- Epilepsy
- Glioblastoma
- Diabetes
Name five possibilities to overcome the BBB.
- Increase lipophilicity of small molecules
- Efflux-inhibition
- Use of drug precursors
- Temporaray damage to BBB
- Use of viral vectors
What is K_o/w ?
- Distribution coefficient beween octanol and water
- Substances with a high K_o/w can translocate easy into the CNS
