Upload
rupert
View
40
Download
0
Embed Size (px)
DESCRIPTION
Neurobiology course 2010 3.5.2010 Group 7. Ivana Mizikova Salla Kangas Henri Urpilainen. Introduction to BBB. Originally found by Paul Ehrlich in 1885 Complementary observations by Edwin Goldman 1913 - PowerPoint PPT Presentation
Citation preview
Neurobiology course 20103.5.2010Group 7
Ivana MizikovaSalla KangasHenri Urpilainen
Introduction to BBB
• Originally found by Paul Ehrlich in 1885
• Complementary observations by Edwin Goldman 1913
• The localisation of the barrier was found: it separates the blood circulation from the brain tissue – the cellular basis was unclear
• BBB is located within endothelium in most vertebrates
Location of barrier sites in the CNS.Abbott NJ et al. (2006) Astrocyte–endothelial interactions at the blood–brain barrierNat. Rev. Neuro. 7: 41–53 doi:10.1038/nrn1824
Endothelial cells• BBB is formed by
endothelial cells, which form the capillars walls
• BBB endothelium differ from other endothelial structures
• BBB characteristics in endothelial cells is not pre-determined, but induced by environment
Abbott NJ et al. (2006) Astrocyte–endothelial interactions at the blood–brain barrierNat. Rev. Neuro. 7: 41–53 doi:10.1038/nrn1824
a) Fenestrated capillary in mouse eyec) Brain capillary in moused) Large vessel in mouse braine) Magnification from d showing the tight
junction
Junctions in endothelium
• Adherens junctions– Cadherins and integrins
• Tight junctions– Structure of tight junction in endothelial cells of
BBB is most complex among the entire vasculature of the body
– Impermeable barrier to fluid formed by closely associated membranes of two cells
Molecular composition of cell junctions
- Occludin (modulators)
- Claudin (barrier properties)
- Peripheral membrane proteins (cytoplasmic plaque, adaptor proteins) Abbott NJ et al. (2006) Astrocyte–endothelial
interactions at the blood–brain barrierNat. Rev. Neuro. 7: 41–53 doi:10.1038/nrn1824
Transporters in the BBB endothelium
• Delivery of vital molecules requires the presence of transporters, which are under the control of astrocytes– DOPA (metabolic BBB)– Glucose (main energy source of the brain)
• P-glycoprotein– Extrusion of nonpolar molecules out of
endothelial cells
Abbott NJ et al. (2006) Astrocyte–endothelial interactions at the blood–brain barrierNat. Rev. Neuro. 7: 41–53 doi:10.1038/nrn1824
The glio-vascular complex
• Involved in the regulation of blood flow and nutrient supply within the CNS
Regulation includes:1) Control of perfusion2) Maintenance of energy supply3) The protection of nervous
parenchyma
Abbott NJ et al. (2006) Astrocyte–endothelial interactions at the blood–brain barrierNat. Rev. Neuro. 7: 41–53 doi:10.1038/nrn1824
• Formed by astrocyte endfeet and pericytes together with endothelial cells
REMEMBER THIS!
• BBB is important barrier that protect the brain tissue from threats
• In the formation of BBB cooperate glial cells (astrocytes), pericytes, endothelial cells and extracellular components
• Specialized transport through BBB plays important role in brain tissue nutrition and homeostasis
• BBB is a dynamic structure under the close regulation of the brain microenvironment by astrocytes and pericytes
Thank you!