Citation, DOI, disclosures and article data
At the time the article was created Frank Gaillard had no recorded disclosures.View Frank Gaillard's current disclosures
At the time the article was last revised Frank Gaillard had the following disclosures:
- Radiopaedia Australia Pty Ltd, Founder and CEO (ongoing)
- Biogen Australia Pty Ltd, Investigator-Initiated Research Grant for CAD software development in multiple sclerosis (past)
These were assessed during peer review and were determined to not be relevant to the changes that were made.View Frank Gaillard's current disclosures
Astrocytes are cells of the central nervous system which act as both physical and physiological support for the neurons that are embedded between them, regulating water movement, facilitating metabolic exchange between neurons and capillaries, as well as responding to mechanical and biochemical insults to the brain (e.g. gliosis) 1.
Astrocytes are divided into two types 2:
- protoplasmic astrocytes
- fibrous astrocytes
Protoplasmic astrocytes are particularly abundant in the grey matter, where they are the most abundant glial cells 1,2. They are highly branched with processes distributed fairly uniformly around the cell body. The end-feet of these processes wrap around blood vessels and form the outermost layer of the blood-brain barrier, the subpial glia limitans 2. They have abundant Aquaporin 4 water channel expression and have a role in regulating extracellular fluid transport (known as the glymphatic pathway).
Fibrous astrocytes are primarily located within the white matter and have fewer and far longer processes, contacting nodes of Ranvier of axons as well as supporting and wrapping around local capillaries 2.