Search results
Results from the WOW.Com Content Network
Although the exact mechanism is not completely understood, astrocytes are known to facilitate changes in blood flow [9] [10] and have long been thought to play a role in waste removal in the brain. [11] Researchers have long known that astrocytes express water channels called aquaporins. [12]
The astrocytes of the glia limitans are responsible for separating the brain into two primary compartments. The first compartment is the immune-privileged brain and spinal cord parenchyma. This compartment contains multiple immunosuppressive cell surface proteins such as CD200 and CD95L and it allows for the release of anti-inflammatory factors.
In the CNS, AQP4 is the most prevalent aquaporin channel, specifically located at the perimicrovessel astrocyte foot processes, glia limitans, and ependyma. [8] In addition, this channel is commonly found facilitating water movement near cerebrospinal fluid and vasculature. [9] Aquaporin-4 was first identified in 1986.
Astrocytes (green) in the context of neurons (red) in a mouse cortex cell culture 23-week-old fetal brain culture human astrocyte Astrocytes (red-yellow) among neurons (green) in the living cerebral cortex. Astrocytes are a sub-type of glial cells in the central nervous system. They are also known as astrocytic glial cells.
Astrocytes may regulate vasoconstriction and vasodilation by producing substances such as arachidonic acid, whose metabolites are vasoactive. Astrocytes signal each other using ATP . The gap junctions (also known as electrical synapses ) between astrocytes allow the messenger molecule IP3 to diffuse from one astrocyte to another.
Since bergmann glia appear to persist in the cerebellum, and perform many of the roles characteristic of astrocytes, they have also been called "specialized astrocytes." [9] Bergmann glia have multiple radial processes that extend across the molecular layer of the cerebellar cortex and terminate at the pial surface as a bulbous endfoot. [11]
Micrograph showing gliosis in the cerebellum. Reactive astrocytes on the left display severe proliferation and domain overlap. Reactive astrogliosis is the most common form of gliosis and involves the proliferation of astrocytes, a type of glial cell responsible for maintaining extracellular ion and neurotransmitter concentrations, modulating synapse function, and forming the blood–brain ...
Astrocytes maintain homeostasis of excitatory substances, such as extracellular potassium, by immediate uptake through specific potassium channels and sodium potassium pumps. It is also regulated by potassium spatial buffering via astrocyte networks where astrocytes are coupled through gap junctions.